The aim of this project is to culture neurons in the laboratory for use in studies of axoplasmic structure and transport. These cultured neurons are also to be used in connection with voltage clamp and patch clamp experiments of ionic channels and their conductances and gating mechanisms. A number of fluorescent immuno-assays have established that neurons, glial, and muscle cells are routinely grown from squid embryos by our method. In collaboration with Alan Hodge, we have found that filopodia of cultured cells undergo a peculiar motility involving a "slip-knot" action. This motility is also present in filopodia of mammalian cell lines but is more easily studied with squid cells. Both high contrast DIC video microscopy and scanning electron microscopy are being utilized along with fluorescent probes.